Flies in the high for floral hike? Altitudinal variation in species diversity and composition of Diptera (Insecta) in the eastern Himalaya, India

Abstract

Species diversity and composition enable us to understand the conservation and management of an ecosystem. There is scarcity of knowledge in understanding the diversity change across the gradients of elevation, especially in the Himalaya. Here, we focused in the eastern Himalaya to investigate the patterns of taxonomic and functional diversity of true flies with relation to variation in altitude. The study was conducted in protected area (Neora Valley National Park) in the eastern Himalaya, India and the survey was conducted at five altitudinal zones (from 500 to 3,000 m). A total of 201 species of Diptera, with 105 genera and 33 families were recorded, of which 25 species are new to the state of West Bengal and eight species are new to India. The species diversity increased with elevation (maximum was near 2,500 m) and most of the flies preferred to be close to bushes with flowers, with a substantial percentage of them being pollinator species. Flies adapt to the various vegetation and climate patterns, which was evident by the abundance of fly species at high altitudes (1,500–2,500 m). Hence, it is very important to implement appropriate actions to protect the diversity of true flies in this Himalayan landscape.